Performing Drosophila Crosses

Collect virgin females with appropriate marker and put into a new vial.
Store the vials from which virgins are collected at 18° C when not using.
Store vials from which males are collected at room temperature.
Once 10 virgin females from a strain have been collected, add 4 males with the appropriate marker from a different strain.
Label the vial to indicate the cross type and generation (A1 = the first generation of the first cross).
Store the crosses in an incubator.
After 5 days, flip the 14 flies into a new vial (there should be eggs visible at the surface of the food).
Label the vial appropriately (A2 = the second generation of the first cross).
Repeat this cycle until enough progeny from the crosses have been produced or until there are no parent males left.
The progeny will start eclosing after ~10 days.
Record the date that the flies begin eclosing.
Once there are at least 20 flies in the vial, collect the progeny and sort according to phenotype.
Record the number of flies of each phenotype born.
Place the males and females into separate vials.
There should be 5 - 15 progeny flies in each vial.
- If necessary, separate/combine phenotypes to have an appropriate number of flies in the vial.
Label the vial with:

Keep the progeny vials in an incubator.
Repeat this process during the six days following the date of first eclosure
- Wait to sort until there are at least 20 flies in the vial (usually 2 to 3 times per vial)
After six days, toss the vial
Flip all progeny vials twice a week

Bridges Lab Protocols